The present invention relates to an ergonomic hand-held tool (10) with a straight edge (13) that is useful for dividing a surface into two regions an exposed region and a shielded regionon either side of the straight edge. The tool facilitates the application or removal of material on the exposed region of a surface while simultaneously protecting the shielded region.
The application or removal of material from a surface takes place in wide variety of scenarios. A few well known instances include painting walls or other structures, staining furniture to a desirable color, and removing rust from metal objects. Industrial applications often require even more precise surface processing, such as using caustic chemicals to treat specific areas of a surface while leaving a second area unchanged. These types of precise surface processing methods require means of distinguishing from a surface area to be processed and a surface area to be left unchanged. The person performing these surface processes obtains a more precise result by distinguishing different sections of a surface and focusing on each in turn.
A glass surface, such as a window pane held in place by a frame, often proves to be one of the more difficult surfaces to treat. It is often desirable, for example, to paint the frame holding a window pane without painting the window itself. Regardless of the careful painting methods involved, a painter often finds that paint spills off the frame and covers part of the window. Dried paint on a window is typically an undesirable result.
Many techniques have evolved to ease the difficulty of painting a window frame without painting the associated window. One of the more common methods is that of applying tape to the window pane right up to the edge of the frame holding the pane. The painter then applies paint to the frame with the expectation that any excess paint will land on the tape instead of the glass window. When the frame is completely painted, the painter removes the tape to reveal a clean glass.
The taping method is not always the answer, however. First of all, applying tape to all of the edges of a window pane may be just as time consuming and difficult as scraping the glass to rid excess paint.
Second, depending on the width of the tape, there is no guarantee that the tape will completely protect the glass. Third, tape will only stick to glass by use of an adhesive, and this adhesive often remains on the glass after removing the tape. In this case, the painter avoids scraping paint off the window, only to be left scraping the tape adhesive off the window instead. Finally, applying a tape border around window frames has implications for the quality of the resulting paint job. If the tape is applied unevenly, then the window frame may be painted unevenly as well, resulting in a sloppy edge.
Due to the problems associated with window taping, some painters have chosen to paint window frames without too much concern for applying paint to the subject window pane. The painter then scrapes the window panes of excess paint after completely painting the frame, leaving a smooth edge of paint between the frame and the window pane.
Scraping window panes of excess paint can be a time consuming and arduous task. The scraping tool must be sharp enough to remove dried paint without scratching or breaking the window. One traditional paint scraping tool used on windows is a razor blade. A razor blade is sufficiently sharp for the job, but a razor blade is very difficult to use by hand. The small size of a razor blade makes it difficult to use for extended periods of time without exhausting or even injuring the user's hand. The razor blade is of limited applications, therefore, because the razor blade is not conducive for use on large windows or a great number of windows that need to be scraped quickly.
The painting industry has recognized the inherent problems incurred when scraping paint from surfaces. Several tools have been previously developed to assist in removing paint from surfaces in a desired fashion. Commercially available scrapers for painting, dry wall processing, putty application, etc. are common in today's construction markets. These tools, however, often suffer the drawback of being uncomfortable to use for extended periods due to handles that do not easily fit the user's grip. Most of these tools also include a blade type of scraper attached to a separate handle. These tools, therefore, include multiple parts that must be assembled to make a complete device.
Fabrication of tools with many pieces is difficult because individual components must be linked together in manufacturing the scraper.
Tools that are useful for processing a surface, such as scrapers for dried paint, have two common deficiencies. First, many tools are too large and cumbersome for detailed work that requires precise processing of one area of a surface while simultaneously leaving a second area of the surface unchanged. For instance, in the paint scraping example, a painter often desires to remove excess paint from a surface right up to a specific edge without damaging paint on the opposite side of the edge. Commonly available tools are inappropriate for these types of applications in which a user seeks precision and detail.
Another problem in commonly available tools for surface processing is that of ergonomics. Common tools, such as paint brushes, hammers, scrapers, etc. typically include handle designs that have been available for centuries. Industries have only recently begun to study the impact that poorly designed handles have on the user's grip, comfort, and associated endurance in using the tool.
The inventor herein determined that a well designed handle is critical for a tool's optimal use. For hand-held tools that are used for extended periods of time in the same or similar position, the handle can be instrumental in a good result. The inventor herein describes and claims a new ergonomic handle that allows extended use with a better grip and less fatigue during extended hand-held use. The ergonomic handle allows for better precision in processing a surface for longer periods of time.
Prior filed patent applications and previously issued patents show that presently available tools are deficient in regard to the two most problematic areasuse on surfaces requiring precise detail and use for extended periods without fatigue caused by a poorly designed handle. A brief review of art relevant to these issues is indicative of deficiencies in the market today.
In regard to better handles on tools, particularly surface processing tools, U.S. Patent Application No. 2002/0104182 A1 (Panfili et al.), published on Aug. 8, 2002 and entitled Ergonomic Drywall Knife, is indicative of a standard tool handle that attempts to include ergonomic improvements. The application recites a handle for a drywall knife that is lighter due to recesses within the inner core of the handle. The Panfili '182 handle also includes finger grips in various positions that supposedly allow diverse grips with better comfort. The Panfili '182 handle is manufactured by a molding process and attached to the drywall knife blade in a separate manufacturing step.
U.S. Pat. No. 5,857,241 issued to Camp, Jr. et al. on Jan. 12, 1999 shows another handle modification, known as a “soft grip handle.” The patent recites a contoured handle for a paint roller, or the like. The patent also shows that the contoured handle comprises a rigid inner core surrounded by a softer outer grip designed to provide a more comfortable fit for the user's hand. The Camp '241 patent also provides ribbing and finger grooves on the outer portion of the handle to enhance the grip quality of a tool with the claimed handle.
The Panfili '182 patent and the Camp '241 patent continue to rely upon variations of the traditional cylindrical handle. The patents provide cushioning and grippers but include only minor enhancements to the known art. These patents also require attaching the claimed handles to other separate components of the overall tool, a step which the manufacturing process.
Another collection of known art attempts to improve tool handles by conforming the shape of the handle to a standard fist grip. This collection includes U.S. Pat. No. 5,692,265 issued to Dalury on Dec. 2, 1997, and Dalury's PCT counterpart WO 99/26516, published on Jun. 3, 1999. These publications show a tool handle shaped for the user to grip around the body of the handle, with the user's fingers fitting into pre-formed finger grooves. The handle would mainly serve in applications such as hammers or wrenches requiring a tight working grip with the user's hand positioned in a fist around the handle.
U.S. Pat. No. 6,145,151 issued to Herron, et al. on Nov. 14, 2000, shows finger grooves in a paint brush handle to add comfort during use. This handle may be used with a scraper head also.
A final collection of tools for processing various surfaces shows fabricated from metals or other formable materials that are curved to fit a user's hand. U.S. Patent Application No. 2003/0024074 A1 published by Hartman on Feb. 6, 2003 shows a handle with a biconcave-shaped cross section that is suitable for a hand tool, a hand tool extension, a tool connector, etc. The handle is designed to replicate the recess formed by the human hand when gripping an elongated object.
U.S. Pat. No. 6,018,836 issued to Williams on Feb. 1, 2000, recites an elongated arch of material of uniform thickness, useful for scraping a surface to rid the surface of unwanted material. A simple arch of metal or other material, however, has the significant drawback of causing discomfort or injury to the user after extended periods. The uniform thickness of the arch would eventually wear on the user's hand, and the article offers no significant means of avoiding that discomfort.
U.S. Pat. No. 6,044,516 issued to Lev on Apr. 4, 2000 recites a surface processing tool in the form of a plastering trowel. The handle of the trowel comprises a sloped, single piece body that is curved to allegedly be more comfortable for the user. The sloped ends of the handle provide a reference finger rest for the index finger to define the longitudinal position of the user's hand along the handle.
Hartman '074, Williams '836, and Lev '516 all require an assembly operation to attach the designated handles to another component of the tool. This assembly adds to the complexity, and therefore the cost, of the resulting tool.
The tools described thus far in this background information attempt to address the need for a more ergonomic handle for a wide variety of tools. These known embodiments, however, require excessive assembly steps to fabricate the final tool. Certain of the handles are also limited in their applications due to the grips that the handles allow within a user's hand. A need continues to exist, therefore, for a surface processing tool that includes an easily manufactured ergonomic handle component that is applicable to a broader array of uses.
The second problem discussed herein is the continued need for surface processing tools that may be used in applications requiring precise detail work. Many surfaces require processing in discrete sections, such as painting, stripping, chemical treating, etc. A sectional surface processing technique gives the processor more control over the surface to achieve a better defined final result. For instance, in painting, a user often desires to apply or remove paint from a specific area of a surface, up to a defined edge, and leave the remainder of the surface unchanged until a later step. In the case of window frame painting, as discussed above, a need exists to enable the painter to remove dried paint from a window without affecting the associated window frame. The painter in this scenario needs a tool to divide a surface into an exposed region from which paint will be removed and a protected region, such as a window frame, on which paint should remain.
Several issued patents have attempted to address the need for a precise surface processing tool, particularly useful in the painting industry. Expired U.S. Pat. No. 5,289,609 issued to Olson on Mar. 1, 1994 recites a guide for cleaning paint from a window. The guide of Olson '609 is designed to be used with a razor blade or other scraping mechanism. In use, the Olson '609 guide is held against a surface so that an end of the guide provides a straight edge defining a line between paint to be removed and paint to remain after scraping. The Olson '609 guide is made of a very thin sheet and provides no comfortable means of gripping the guide. The Olson '609 apparatus, therefore, suffers the previously discussed problem of user fatigue or even injury after prolonged use. The only means for holding the Olson '609 guide is by pinching the guide between two fingers, a position that is not ergonomically beneficial to the user's hand.
U.S. Pat. No. 6,523,219 issued to Anderson on Feb. 25, 2003, provides a scraper guide assembly that includes a side shield to be placed against a window frame or similar surface. A separate tool is used with the Anderson '219 guide to scrape material off of a surface. Anderson '219 recites a traditional cylindrical handle that lacks a convenient ergonomic quality. The Anderson '219 tool furthermore requires the handle and the side shield to be fabricated separately and assembled by traditional means. This assembly requires more effort and increases the cost of manufacturing a complete tool.
The publications discussed above show a definite need for an apparatus that includes an ergonomic handle without requiring specialized assembly and costly manufacturing processes for fabrication. Tools available in today's marketplace also lack optimal utility in applications that require extra degrees of precision in processing or treating a surface. The inventors herein meet these needs with invention described and claimed herein.
The publications cited above generally relate to the painting industry, and painting is a good example of the utility of the claimed invention. The inventors, however, describe and claim the invention in terms of broader applications for a variety of uses. The more specialized features of the invention are highlighted with illustrations in the context of scraping paint. The paint scraping uses of the claimed invention are for the ease of example only. Unless specifically claimed in a particular embodiment, the use of the ergonomic shielding tool in painting applications is not intended to limit the scope of the claimed invention herein.